Prestress Force Prediction for Concrete Beams with Parabolic Tendon considering Second-Order Deflections

• Main Authors: AHMED ABDELFATAH SADDEK, 薩安莫
• Other Authors: Lin, zu-Kang
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/27w3rd

碩士 === 國立交通大學 === 土木工程系所 === 107 === The deflected shape of a post–tensioned concrete beam with a parabolic tendon, subjected to an additional vertical load, was short-term measured in several laboratory experiments. The “compression–softening” theory was applied in this study. Currently, due to the conflicts among existing theories, the analytical solution for properly considering the structural behavior of these prestressed members is not clear. Thus, more ways had been tried to make the analytical displacements more similar to the experimental displacements. A series of experiments were conducted on a PC beam specimen of high strength concrete with a parabolic bonded tendon for a period of approximately 2.5 months. Specifically, the simply supported PC beam was subjected to the static tests under progressive short–term prestress losses. Conversely, the relationship between static deflection shape and prestress force is well described by the magnification factor formula of compression–softening theory taking into account the secant elastic modulus. Furthermore, according to the “compression-softening” theory, the Song’s formula (2000) was applied on the concrete beam with a parabolic tendon. Finally, after all these modifications, it has been possible to predict the flexural displacements for the concrete beam with a parabolic tendon.